Purpose: This is a phase I, open-label, rising, multiple-dose study designed to characterize the safety profile and determine the maximally-tolerated dose and dose-limiting toxicity of SCH 66336 when administered orally to adult patients with advanced cancer. SCH 66336 is an FTP inhibitor and represents a new class of antineoplastic compounds. It was developed by Schering Plough and has not yet been tested in humans. Methods: Patients receive a single-dose of SC 66336 followed by a 24 hour observation period (cycle l only). Subjects will then receive SC 66336 twice daily for 13 consecutive days. At each dose level, pharmacokinetic evaluations are performed on day 1 and day 14. Patients are admitted to the Clinical Research Center for monitoring and pharmacokinetics for their first dose and repeat pharmacokinetics on day 14. Results: Three patients have experienced dose-limiting toxicity (elevated creatinine, fatigue, nausea, diarrhea). DLT was reached at 300 mg. The primary toxicities appear to be diarrhea and fatigue, which are quickly reversible after discontinuing study drug. Most patients experienced grade 2 symptoms. At Dr Hurwitz' request, the study sponsor granted an extension for an additional four patients enrolled at 200 mg. Future Plans: No further patients are being recruited, although patients are still being treated on study.